Muscle growth stands as a pivotal economic trait within pig production, governed by a complex interplay of multiple genes, each playing a role in its quantitative manifestation. Understanding the intricate regulatory mechanisms of porcine muscle development is crucial for enhancing both pork yield and quality. This study used the GSE99749 dataset downloaded from the GEO database, conducting a detailed analysis of the RNA-seq results from the longissimus dorsi muscle (LD) of Tibetan pigs (TP), Wujin pigs (WJ) and large white pigs (LW) at 60 days of gestation, representing diverse body sizes and growth rates. Comparative analyses between TPvsWJ and TPvsLW, along with differential gene expression (DEG) analysis, functional enrichment analysis, and protein–protein interaction (PPI) network analysis, revealed 1048 and 1157 significantly differentially expressed genes (p < 0.001) in TPvsWJ and TPvsLW, respectively. With stricter screening criteria, 37 DEGs were found to overlap between the 2 groups. PPI analysis identified MYL5, MYL4, and ACTC1 as the three core genes. This article focuses on exploring the MYL4 gene. Molecular-level experimental validation, through overexpression and interference of the MYL4 gene combined with EDU staining experiments, demonstrated that overexpression of MYL4 significantly promoted the proliferation of porcine skeletal muscle satellite cells (PSMSC), while interference with MYL4 inhibited their proliferation. Furthermore, by examining the effects of overexpressing and interfering with the MYL4 gene on the muscle hypertrophy marker Fst gene and the muscle degradation marker FOXO3 gene, the pivotal role of the MYL4 gene in promoting muscle growth and preventing muscle degradation was further confirmed. These findings offer a new perspective on the molecular mechanisms behind porcine muscle growth and development, furnishing valuable data and insights for muscle biology research.

The purpose of this study was to explore and verify genes that regulate the reproductive traits of Tibetan pigs at the mRNA level. The ovarian tissues of Tibetan pigs (TPs) and Yorkshire pigs (YPs) were selected as research objects, and cDNA libraries of the ovarian tissue transcripts of Tibetan pigs and Yorkshire pigs were successfully constructed by the RNA-Seq technique. A total of 651 differentially expressed genes (DEGs) were screened, including 414 up-regulated genes and 237 down-regulated genes. Through GO and KEGG enrichment analysis, it was found that these differentially expressed genes were significantly enriched in cell process, reproductive process, reproduction, cell proliferation, binding, and catalytic activity, as well as oxidative phosphorylation, endocrine resistance, thyroid hormone, Notch, and other signal transduction pathways. Genes significantly enriched in pathways closely related to reproductive regulation were analyzed and selected, and the AR, CYP11A1, CYP17A1, INHBA, ARRB2, EGFR, ETS1, HSD17B1, IGF1R, MIF, SCARB1, and SMAD4 genes were identified as important candidate genes. Twelve differentially expressed genes related to reproduction were verified by RT-qPCR. The results showed that the expression of the AR, CYP17A1, EGFR, ETS1, IGF1R, and SMAD4 genes was significantly higher in Tibetan pigs than in Yorkshire pigs, while the expression of the CYP11A1, INHBA, ARRB2, HSD17B, MIF, and SCARB1 genes in Tibetan pigs was significantly lower than in Yorkshire pigs. The purpose of this study is to provide a theoretical basis for exploring the molecular mechanism of reproductive trait effect genes and the application of molecular breeding in Tibetan pigs.

Background/Objectives: The aim of this study was to explore the effects of diets with different protein levels on the metabolite composition and metabolic pathways of the longest dorsal muscle of Tibetan pigs, in order to provide a metabolic basis for optimizing the nutritional regulation strategy of Tibetan pigs. Methods: A total of 32 healthy 180-day-old depopulated male Tibetan pigs were randomly divided into four groups and fed diets with protein levels of 10%, 12%, 14%, and 16%, respectively, with a feeding cycle of 8 weeks. The longest dorsal muscle samples were collected, and their metabolic profiles were systematically analyzed by LC-MS non-targeted metabolomics. Results: The TIC plots of the quality control samples were highly overlapped, indicating a stable instrumental detection process and good consistency of sample processing. Principal component analysis and orthogonal partial least squares discriminant analysis revealed significant metabolic differences between groups with different protein levels. A total of multiple differential metabolites was obtained based on VIP value and p-value screening, and Venn diagram analysis revealed a total of 11 metabolites among the three comparative groups, suggesting that they may have key roles in the protein regulation process. Volcano plots further clarified the number and trend of significantly up- and down-regulated metabolites in each group. KEGG pathway enrichment analysis showed that, with the elevation of protein level, the metabolic pathway response showed a tendency of expanding from basal energy metabolism to the complex network of amino acid synthesis, steroidogenesis, endocrine signaling, and detoxification pathways, especially in the high-protein-treated group. Conclusions: The study showed that different protein intake levels could significantly regulate the metabolites and key metabolic pathways in the longest muscle of Tibetan pigs, which provided theoretical support for the scientific formulation of a protein supply program to optimize the quality and growth performance of Tibetan pork.

Ammonia gas (NH₃) is a major hazard in animal husbandry that negatively affects animal growth and reproductive activities. Although the adverse effects of ammonia on livestock health and performance have been studied, its specific effects on the male reproductive system and its underlying biological mechanisms remain unclear. The aim of this study was to investigate the effects of ammonia exposure on male reproduction and its potential mechanisms of action. Immunohistochemistry revealed a significant increase in IL-10 expression in mouse testicular tissues under ammonia-induced stress. Ammonia exposure significantly decreased anti-apoptotic factor Bcl-2 and anti-autophagy factor p62 expression, coupled with increased expression of pro-apoptotic factors, including p53, Caspase-8, Bax, and Apaf, as well as the pro-autophagy factors Beclin1, ATG5, LC3B, the ratio of Bax/Bcl-2 and the ratio of P53/Bcl-2. The fluorescence intensity of the Cyt C apoptotic gene and pro-autophagy factor LC3B in immune tissues was significantly higher than that in the normal control group. In summary, ammonia exposure significantly affects the reproductive ability of male mice by inducing inflammation, apoptosis, and autophagic damage in the testes. Our findings provide insights into ammonia-induced reproductive disorders, which will contribute to the management and control of ammonia in animal husbandry, thereby reducing the negative effects of ammonia on the reproductive health of livestock and poultry and improving the quality and yield of livestock products.

Pig manure, as an organic fertilizer, can significantly affect soil nutrient content, pH, and electrical conductivity. Moreover, the accumulation of heavy metals in pig manure and their potential ecological risks are also important concerns in soil management. Additionally, grazing systems may influence soil health and ecological balance by altering the soil microbial community structure. Therefore, this study investigates the impact of grazing Tibetan pigs on soil quality, focusing on the physicochemical properties, heavy metal accumulation, and microbial diversity. In the surface soil after grazing (GS0), pH, EC, AP, and AK were significantly higher than before grazing (NS0) (p < 0.05), while AN showed no significant difference. In the 10 cm soil layer, pH, EC, AK, and AN in GS10 were significantly higher than in NS10 (p < 0.05), whereas AP was significantly lower (p < 0.05). At the 20 cm depth, pH, EC, AP, and AK in GS20 were significantly higher than in NS20 (p < 0.05), but AN was significantly lower (p < 0.05). Overall, AN, AP, and AK decreased with increasing soil depth, while pH and EC showed no significant changes between the 10 cm and 20 cm layers (p > 0.05). In GS0 soil, the contents of Cd(II) and Zn(II) were significantly lower than those in NS0 (p < 0.05), while Pb(II) content was significantly higher (p < 0.05). There were no significant differences in Cu(II), Ni(II), Cr(VI), As(V), and Hg(II) (p > 0.05). In GS10 soil, Ni and Pb(II) contents were higher, whereas Cu(II), Zn(II), and Hg(II) contents were lower. In GS20 soil, Pb(II) and Cr(VI) contents were higher, while Cu(II) and Zn(II) contents were lower. Overall, GS had consistently lower Cd(II), Cu(II), Zn(II), and Hg(II) contents at all depths compared to NS, while Pb(II) and Cr(VI) contents were higher, showing depth-related variation trends, possibly due to plant absorption and heavy metal leaching. Probiotics such as Firmicutes, Bacteroidetes, and Acinetobacter increased significantly in soil, resulting in changes in the soil bacterial community.

Background: The Tibetan pig, a highland breed with exceptional adaptability to harsh environments (cold, hypoxia, coarse feed) but poor growth/reproductive traits, was studied to uncover genetic mechanisms and support breeding improvements. Methods: We conducted de novo genome assembly of a male Tibetan pig using stLFR sequencing, supplemented with ONT data, and compared the assembly to the Duroc pig genome (v11.1). Results: The assembled genome (2.25 Gb, contig N50 = 136.5 Mb, GC content = 41.74%, 94.16× coverage) showed 96.9% BUSCO completeness. Structural variant (SV) analysis identified 22,008 insertions and 27,639 deletions, with an SV genotyping accuracy of 0.9735. Selective sweep analysis highlighted adaptive genes: XIRP2 (cardiac function), KSR2/CACNA1A (fat metabolism), COL11A1 (cartilage), and ADORA2A (vascular regulation). Tibetan pigs exhibited the fewest and shortest runs of homozygosity (ROHs) among four breeds, with ROH-linked SNPs implicating lipid catabolism genes (LIPE, PNPLA2, MGLL, DGAT1). An SNP-based GWAS revealed reproductive trait associations: immune gene IL2RB, energy metabolism genes PRKAG2, ADGRA1, and PTPRN2, and growth genes SLIT2 and BMP6. SV analysis identified additional candidates: energy metabolism genes HAO2 and NRG4, growth genes MTUS2 and FGF12, and immune genes SCGB1A1 and C8A. Conclusions: This study provides a chromosome-level genome assembly of a male Tibetan pig (generated from stLFR and ONT data), and, through whole-genome resequencing of 124 Tibetan sows, identifies key genetic factors underlying Tibetan pigs’ environmental adaptability and reproductive limitations, enabling genomic strategies to enhance breeding efficiency while preserving adaptive traits.